Modifying the RabbitMQ Cluster Operator Default Configuration

This information describes how to modify the configuration of the RabbitMQ Cluster Kubernetes Operator in a Kubernetes cluster. You might want to do this to control how the Cluster Operator configures RabbitmqClusters. For example, it can be useful when you are configuring the operator to automatically use the RabbitMQ container images that are stored in a private registry.

To change the configuration, add or update the configuration environment variables by editing the Cluster Operator deployment manifest. This is the YAML manifest artefact that is released with every new version of the RabbitMQ Cluster Operator on GitHub. The environment variables that can be set are listed in the table in Cluster Operator Environment Variables.

The Cluster Operator repository has some code examples under docs/examples, including one demonstrating modification of default resource requests and limits.

Adding Cluster Operator Environment Variables to the Deployment Manifest

When the Cluster Operator is deployed, update the manifest by completing the following steps:

1. Run:

   kubectl -n rabbitmq-system edit deployment rabbitmq-cluster-operator
2. Add the environment variables you want to change. In the following example, the OPERATOR_SCOPE_NAMESPACE environment variable is added and set to "custom-namespace,my-namespace" for the Cluster Operator.

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     labels:
       app.kubernetes.io/component: rabbitmq-operator
       app.kubernetes.io/name: rabbitmq-cluster-operator
       app.kubernetes.io/part-of: rabbitmq
     name: rabbitmq-cluster-operator
     namespace: rabbitmq-system
   spec:
     template:
       spec:
         containers:
         - command:
           - /manager
           env:
           - name: OPERATOR_NAMESPACE
             valueFrom:
               fieldRef:
                 fieldPath: metadata.namespace
           - name: OPERATOR_SCOPE_NAMESPACE
             value: "custom-namespace,my-namespace"
   # ...
3. Save the manifest. The Cluster Operator Pod is updated to use this configuration.

Important: Future GitHub releases for the RabbitMQ Cluster Operator will not have your changes. Therefore, these updates must be synced every time the Cluster Operator is updated. Consider using templating to add these variables automatically. For example, using a ytt overlay.

Example of Using ytt overlay to add Cluster Operator Environment Variables Automatically

values.yaml

#@ load("@ytt:overlay", "overlay")
#@ deployment = overlay.subset({"kind": "Deployment"})
#@ cluster_operator = overlay.subset({"metadata": {"name": "rabbitmq-cluster-operator"}})
#@overlay/match by=overlay.and_op(deployment, cluster_operator),expects="1+"
---
spec:
  template:
    spec:
      containers:
      #@overlay/match by=overlay.subset({"name": "operator"}),expects="1+"
      -
        #@overlay/match missing_ok=True
        env:
        - name: OPERATOR_SCOPE_NAMESPACE
          value: custom-namespace

Use this overlay when upgrading the operator to ensure your custom configuration is applied for the new version:

ytt -f https://github.com/rabbitmq/cluster-operator/releases/latest/download/cluster-operator.yml -f values.yaml | kubectl apply -f -

Cluster Operator Environment Variables

The following table listes the Cluster Operator environment variables that are available to set in the deployment manifest.

Variable Name	Effect when Set	Effect when not Set
OPERATOR_SCOPE_NAMESPACE	Namespace, or list of namespaces, which the operator will reconcile and watch RabbitmqClusters (independent of installation namespace). Use a comma separator, without spaces e.g. "project-1,project-2,rabbitmq-testing"	All namespaces are watched and reconciled
DEFAULT_RABBITMQ_IMAGE	RabbitMQ container image used for new RabbitmqCluster Pods where not explicitly set in RabbitmqCluster.Spec.Image	Operator uses the latest RabbitMQ container image available at time of release for new Pods
DEFAULT_USER_UPDATER_IMAGE	Vault sidecar container image used for new RabbitmqCluster Pods where not explicitly set in RabbitmqCluster.Spec.SecretBackend.Vault.DefaultUserUpdaterImage	Operator uses the latest sidecar container image available at time of release for new Pods
DEFAULT_IMAGE_PULL_SECRETS	Comma-separated list of imagePullSecrets to set by default on all RabbitmqCluster Pods where not explicitly set in RabbitmqCluster.Spec.ImagePullSecrets	New RabbitmqCluster Pods have no imagePullSecrets by default
ENABLE_DEBUG_PPROF	The default value is false because this variable should NOT be used in production. When it is set to true, it exposes a set of debug endpoints on the Operator Pod's metrics port for CPU and memory profiling of the Operator with pprof.	The pprof debug endpoint will not be exposed on the Operator Pod.
CONTROL_RABBITMQ_IMAGE	EXPERIMENTAL! When this is set to true, the operator will always automatically set the default image tags. This can be used to automate the upgrade of RabbitMQ clusters, when the Operator is upgraded. Note there are no safety checks performed, nor any compatibility checks between RabbitMQ versions.	The Operator does not control the image. The user is responsible for updating RabbitmqCluster image.
LEASE_DURATION	Time, in seconds, that non-leader candidates will wait to force acquire leadership. This is measured against time of last observed ack. Default is 15 seconds. The value must be a string e.g. "30".	Default value is set to 15 seconds.
RENEW_DEADLINE	Renew deadline is the duration that the acting controlplane will retry refreshing leadership before giving up. Default is 10 seconds. The value must be a string e.g. "10".	Default value is set to 10 seconds.
RETRY_PERIOD	Retry period is the duration the LeaderElector clients should wait between tries of actions. Default is 2 seconds. The value must be a string e.g. "3".	Default value is set to 2 seconds.